Custom HTML code for Webflow

For this project you will already need to have an upgraded Webflow account to use the embed HTML code feature. When a user signs up to my website and logs in there is a message of what email session in the inspector under console. I want a custom html embed script to check match the id of the console in column id in my Google sheets. So the script should look up and find the same email adress row id that is currently logged into the session and then pull the data to webflow elements and populate existing elements. The CSS styling and class should be linked to the existing webflow page. I don't want new elements getting added from your code just changing existing elements.